Haseeba, K.P.; Al-Khayat, J.A.; Jabir, T.; Shafeeq, H.; Veerasingam, S.; Talaat, A., and Vethamony, P., 2024. Metagenomic approach to assess the bacterial communities in the tarmats of the Qatar coast, Arabian Gulf. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 870-874. Charlotte (North Carolina), ISSN 0749-0208.

Tarmats are oil-sediment agglomerates containing hydrocarbons (including polycyclic aromatic hydrocarbons), and can pose significant environmental risks. In this work, microbial diversity and community composition associated with tarmat deposits along the heavily impacted northwest and northeast coasts of Qatar have been investigated based on 16S rRNA amplicon sequencing. Core genera were determined using the Dirichlet multinomial mixture approach. The bacterial classes, γ-proteobacteria (30%) and α-proteobacteria (20%) were abundant in the tarmat. Nine genera, which were previously recorded as potential hydrocarbon degraders, have been identified as core microbiota. Their abundance showed significant variation between the northwest and northeast coasts. The genera, Alkalilimnicola sp. Thermodesulfobacterium sp., Anaerophaga sp., Marinobacter sp., and Spirochaeta were predominant on the northwest coast, whereas, the northeast coast was dominated by Alcanivorax sp, Alteromonas sp and Tepidamorphus sp. Acidithiobacillaceae (KCM-B-112) exhibited similar abundance levels in both the coastal regions. The highest tarmat bacterial diversity and richness were observed in the northwest coast of Qatar. The present study is the first investigation of bacterial communities associated with tarmat deposits along the Qatar coast.